A conventional inkjet printing system, as one embodiment of a fluid ejection system, includes a printhead, an ink supply which supplies liquid ink to the printhead, and an electronic controller which controls the printhead. The printhead, as one embodiment of a fluid ejection device, ejects ink drops through a plurality of orifices or nozzles and toward a print medium, such as a sheet of paper, so as to print onto the print medium. Typically, the orifices are arranged in one or more arrays such that properly sequenced ejection of ink from the orifices causes characters or other images to be printed upon the print medium as the printhead and the print medium are moved relative to each other.
In some fluid ejection devices, such as printheads, a plurality of drop ejecting elements are formed on a substrate and fluid is routed to ejection chambers of the drop ejecting elements through a slot or opening in the substrate. Unfortunately, air bubbles and/or particles which can degrade operation of the fluid ejection device may collect within the opening of the substrate. In addition, heat which can also affect operation of the fluid ejection device may be generated during operation of the drop ejecting elements.
Accordingly, it is desired to circulate fluid through the fluid ejection device to facilitate the removal of air bubbles from and/or dissipate heat generated in the fluid ejection device.